1. Field
Exemplary embodiments of the present invention relate to a method for fabricating a semiconductor device, and more particularly, to a semiconductor device with a silicon-containing hard mask and a method for fabricating the same.
2. Description of the Related Art
In general, patterns constituting a semiconductor device are formed by forming hard mask patterns over an etch target layer to be patterned and etching the etch target layer exposed between the hard mask patterns. When the hard mask patterns serving as an etch barrier are used to perform the etch process, the etch target layer under the hard mask patterns must not be exposed while the etch target layer exposed between the hard mask patterns is etched. However, as the patterns of the semiconductor device are highly integrated, the ratio of a thickness to be etched to a width to be etched (referred to as aspect ratio) of the etch target layer has increased. Accordingly, while the etch process is performed, the hard mask patterns may be removed. This is because, as the aspect ratio increases, the hard mask pattern having a smaller thickness than the etch target layer may be lost during the etch process. To solve such a problem, the hard mask pattern may be formed to a larger thickness. In this case, however, the aspect ratio of the hard mask pattern also increases. When the aspect ratio of the hard mask pattern increases, it is difficult to perform a stable etch process for forming the hard mask pattern as in the etch process for the etch target layer. For example, when a thick hard mask layer is etched, bowing may occur, and the etch process for the etch target layer under the hard mask layer may be influenced by the bowing occurring in the hard mask pattern.